Press machine

Abstract

A press machine comprising a base, a guide member provided in such a manner that an end thereof orthogonally intersects the base, a support plate provided in such a manner that the other end of the guide member orthogonally intersects the guide member, a screw shaft supported by the support plate in parallel with the guide member, a nut member engaging with the screw shaft, and a movable body; the movable body consisting of a first movable body and a second movable body, both facing each other, obtained by dividing the movable body at a surface intersecting the traveling direction of the movable body; the first and second movable bodies connecting each other via a differential member formed in such a manner as to slidably engage with the first and second movable bodies; the differential member formed in such a manner as to be movable in a direction orthogonally intersecting the traveling direction of the movable body; and the first and second movable bodies adapted to be relatively movable along the traveling direction of the movable body along with the movement of the differential member.

What is claimed is:  
     
       1. A press machine comprising: 
       a base with a table surface for supporting a workpiece;  
       a guide member having one end connected to said base;  
       a support plate connected to another end of said guide member;  
       ball screw arrangement having screw shaft, a nut member and a plurality of balls between said screw shaft and said nut member;  
       a slide plate being movable in a pressing direction toward and away from said base;  
       said support plate rotatably connected to said screw shaft of said ball screw arrangement;  
       a movable device adjusting a distance between said slide plate and said table surface in said pressing direction, said movable device includes a first movable body and a second movable body, said movable device includes a differential member arranged between, and slidably engaging with, said first and second movable bodies, said differential member being movable in an adjusting direction substantially orthogonal to said pressing direction, said first and second movable bodies and said differential member being shaped to have movement of said differential member with respect to said first and second movable bodies cause said first and second movable bodies to expand and contract in said pressing direction, expanding and contracting of said movable bodies adjusting said distance in said pressing direction between said slide plate and said table surface;  
       a press motor connected to said screw shaft and rotatable of said screw shaft;  
       an adjustment motor connected to said differential member and movable of said differential member in said adjusting direction;  
       a control unit controlling said press motor to move said slide plate between a first and second position with respect to said table surface, said control unit also controlling said adjustment motor to move said differential member, said control unit adjusting operation of said pressing motor to maintain said slide plate moving between said first and second positions so that said distance between said first and second positions is kept constant after said adjustment motor moves said differential member.  
     
     
       2. A press machine as set forth in  claim 1  wherein a pair of guide plates are provided on both side surfaces of the first and second movable bodies in such a manner as to slidably engage with the first and second movable bodies so that the movement of the first and second movable bodies in the direction orthogonally intersecting the direction of relative movement of the first and second movable bodies can be constrained. 
     
     
       3. A press machine as set forth in  claim 1  wherein the base and the support plate are disposed in parallel with a horizontal plane, and an axial line of the guide member is disposed vertically. 
     
     
       4. A press machine as set forth in  claim 1  wherein the screw shaft and/or the differential member are driven by a pulse motor. 
     
     
       5. A press machine in accordance with  claim 1 , wherein: 
       said movable device is arranged between said screw shaft and said slide plate.  
     
     
       6. A press machine in accordance with  claim 1 , wherein: 
       said control unit operates said adjustment motor after a predetermined number of movements of said slide plate between said first and second positions.  
     
     
       7. A press machine in accordance with  claim 1 , wherein: 
       said control unit operates said adjustment motor to substantially evenly wear said ball screw arrangement from movements of said slide plate between said first and second positions.  
     
     
       8. A press machine in accordance with  claim 1 , wherein: 
       said ball screw arrangement includes a ball groove on said screw shaft and a plurality of balls arranged in said ball groove.  
     
     
       9. A method for operating a press machine, the method comprising the steps of: 
       providing a base with a table surface for supporting a workpiece;  
       providing a guide member having one end connected to said base;  
       providing a support plate connected to another end of said guide member;  
       providing a screw shaft rotatably connected to said support plate;  
       providing a slide plate rotatably connected to said screw shaft with a ball screw arrangement, said ball screw arrangement having rotation of said screw shaft cause movement of said slide plate in a pressing direction toward and away from said base;  
       providing a movable device adjusting a distance between said slide plate and said table surface in said pressing direction, said movable device includes a first movable body and a second movable body, said movable device includes a differential member arranged between, and slidably engaging with, said first and second movable bodies, said differential member being movable in an adjusting direction substantially orthogonal to said pressing direction, said first and second movable bodies and said differential member being shaped to have movement of said differential member with respect to said first and second movable bodies cause said first and second bodies to expand and contract in said pressing direction, expanding and contracting of said movable bodies adjusting said distance in said pressing direction between said slide plate and said table surface;  
       rotating said screw shaft to repetitively move said slide plate between a first and second position with respect to said table surface;  
       moving said differential member to expand and contract said movable device;  
       adjusting said rotating of said screw shaft to maintain said slide plate moving between said first and second position after said moving of said differential member.  
     
     
       10. A method in accordance with  claim 9 , wherein: 
       said moving of said differential member is performed after a predetermined number of movements of said slide plate between said first and second positions.  
     
     
       11. A method in accordance with  claim 9 , wherein: 
       said moving of said differential member is performed to substantially evenly wear said ball screw arrangement as occurring due to movements of said slide plate between said first and second positions.  
     
     
       12. A method in accordance with  claim 9 , wherein said moving of said differential member is performed after every movement of said said slide plate from said first position to said second position, and back to said first position. 
     
     
       13. A press machine in accordance with  claim 1 , wherein: 
       said control unit operates said adjustment motor each time said slide plate moves from said first position to said second position and back to said first position.  
     
     
       14. A press machine in accordance with  claim 1 , wherein: 
       said first movable body is unrotatably connected to said nut member and said second movable body is unrotatably connected to said slide plate.  
     
     
       15. A press machine comprising: 
       a base with a table surface for supporting a workpiece;  
       a guide member having one end connected to said base;  
       a support plate connected to another end of said guide member;  
       a screw shaft rotatably connected to said support plate;  
       a slide plate rotatably connected to said screw shaft with a ball screw arrangement, said ball screw arrangement having rotation of said screw shaft cause movement of said slide plate in a pressing direction toward and away from said base;  
       a movable device adjusting a distance between said slide plate and said table surface in said pressing direction, said movable device includes a first movable body and a second movable body, said movable device includes a differential member arranged between, and slidably engaging with, said first and second movable bodies, said differential member being movable in an adjusting direction substantially orthogonal to said pressing direction, said first and second movable bodies and said differential member being shaped to have movement of said differential member with respect to said first and second movable bodies cause said first and second bodies to expand and contract in said pressing direction, expanding and contracting of said movable bodies adjusting said distance in said pressing direction between said slide plate and said table surface;  
       a press motor connected to said screw shaft and rotatable of said screw shaft;  
       an adjustment motor connected to said differential member and movable of said differential member in said adjusting direction;  
       a control unit controlling said press motor to move said slide plate between first and second distances from said table surface, said control unit also controlling said adjustment motor to move said differential member, said control unit adjusting operation of said pressing motor to maintain said slide plate moving between said first and second distances from said table surface when said adjustment motor moves said differential member.  
     
     
       16. A press machine in accordance with  claim 15 , wherein: 
       said movable device is connected on one side to said screw shaft and connected on an opposite side to said slide plate.  
     
     
       17. A press machine in accordance with  claim 15 , wherein: 
       said control unit operates said adjustment motor after a predetermined number of movements of said slide plate between said first and second distances.  
     
     
       18. A press machine in accordance with  claim 15 , wherein: 
       said control unit operates said adjustment motor to substantially evenly wear said ball screw arrangement from movements of said slide plate between said first and second distances.  
     
     
       19. A press machine in accordance with  claim 15 , wherein: 
       said ball screw arrangement includes a ball groove on said screw shaft and a plurality of balls arranged in said ball groove.